1. Field of the Invention
The present invention relates to systems and methods for transcieving data, and in particular to a system and method for transcieving data and clock information sharing a single data stream using channel coding.
2. Description of the Related Art
It is often necessary or desirable to monitor or control the performance and operating characteristics of remotely disposed systems such as aircraft, missiles, and spacecraft. Monitored information is typically transmitted by a telemetry subsystem on the monitored system to a remote location (typically, terrestrially located).
FIG. 1 is a diagram of a exemplary telemetry system 100 used to monitor satellite data. In this illustrative embodiment, a satellite 102 includes a telemetry transmission system 112 that collects data from satellite subsystems of interest, combines that data into a plurality of channels, and transmits a signal 110 with the channels of information to a telemetry ground system 104. Using antenna 106, the telemetry receiver 108 of the telemetry ground system 104 receives the signal, separates the signal into the plurality of channels, and provides the resulting data to external systems. In many implementations, the data comprises a series of constant period digital pulses of ones and zeros representing a serial data stream. Such signals are generated by a telemetry clock on the satellite 102, and must be replicated at the telemetry ground system 104 to recover the data. Typically, one of the channels of the signal 110 is dedicated to the transmission of a this telemetry clock.
In an idealized system, the telemetry system 100 would provide any number of desired channels, and each of the channels of information could be transmitted with infinite bandwidth. However, real systems offer neither infinite channel capacity or infinite bandwidth. In truth, both the number of available channels and the bandwidth available on each channel are typically limited, requiring the system designer to omit potentially useful information from the data stream. Further, as described above, real systems typically dedicate a channel to transmit a clock that is used to recover the data in the telemetry ground system, removing that channel for use to transmit data.
What is needed is a system that can transmit both the data clock and the data itself on a single channel. The present invention satisfies that need.